1912.] On the Extrusion of Granules by Trypanosomes. 393 



Fig. 7. — Four form (early), the macronuclei have evidently recently divided. The two 

 lower are moving away from each other ; the upper have not completely 

 separated. 



,, 8. — More advanced four form ; all the pairs of macro- and micronuclei have moved 



away from each other. 

 ,, 9. — Eight form, a large body of cytoplasm whose margin shows a few indentations 



as if there might later be division of the whole mass at these situations. All 



the macro- and micronuclei and flagella can be seen. 

 „ 10. — Eight form beginning apparently to divide ; the cytoplasm shows lines of 



cleavage along the lower part of the outline. 

 „ 11. — Mass of 16 bodies breaking up. These resemble the Leishman-Donovan body ; 



each has a macro- and micronucleus, but no flagellum. 

 „ 12. — A large form with single macronucleus and large micronucleus showing fan- 

 shaped origin to flagellum. 

 „ 13. — The body is rounded and has a clear blue-staining cytoplasm. The flagellum 



shows the fan-shaped origin well and stands straight out from the body. 



The micronucleus lies close to the macronucleus. 

 „ 14 and 15. — The body is longer, and the flagellum is lying along the margin ; the 



micronucleus is now moving away from the macronucleus. 

 „ 16, 17, and 18. — These features are more marked, and the specimens show gradual 



approximation to adult type. The flagellum is seen to be separated at some 



point from the outline of the trypan osome body, the earliest stage in the 



development of an undulating membrane. 

 „ 19. — The undulating membrane is now clearly present, but the trypanosome can 



still be recognised as immature by the fan-shaped origin of the flagellum and 



the pale homogeneous cytoplasm. 

 „ 20. — An early adult trypanosome ; the flagellum no longer shows the fan-shaped 



origin, and is much longer. Early granules can be seen in the cytoplasm. 



VOL. LXXXVI. — B. 



